Simultaneous use of two high speed downlink packet access (HSDPA) downlink carriers was introduced as part of the Release 8 of the third generation partnership project (3GPP) wireless code division multiple access (WCDMA). This feature improves the bandwidth usage via frequency diversity and resource pooling. As the data usage continues to increase rapidly, high speed packet access (HSPA) deployment is foreseen to be deployed in more than two downlink carriers. For example, four carrier HSDPA (4C-HSDPA) may allow up to four carriers to operate simultaneously to achieve higher downlink throughput.
Feedback information such as positive acknowledgement/negative acknowledgement (ACK/NACK) information for hybrid automatic repeat request (HARQ) and channel quality indication (CQI) information may indicate the downlink channel conditions. Feedback information may be transmitted to the network over the high speed dedicated physical control channel (HS-DPCCH) feedback channel in the uplink. However, current technologies may not accommodate sending feedback information for multiple carriers such as three or more carriers. Therefore, there is a need for feedback transmission mechanisms that may allow the network to transmit in more than two carriers simultaneously, allow a wireless transmit/receive unit (WTRU) to acknowledge data reception for more than two carriers, and allow multiple the data streams if MIMO is configured.